The overall goal of this project is to determine whether the induction of the inflammatory response involving activation of caspase-1 and processing of interleukin-12 (IL-12) following moderate cervical spinal cord injury (SCI) in the rat is mediated by the formation of multiprotein inflammatory caspase-activating platforms termed inflammasomes. Our recent work has shown that the NLRP1 inflammasome is expressed in rat spinal cord neurons and regulates IL-12 and IL-18 production. We have found that in SCI neutralization of the adaptor protein apoptosis-associated speck-like protein containing a caspase-activating recruitment domain (ASC) reduced inflammation and resulted in significant tissue sparing and functional improvement. The Specific Aims of this proposal will extend these results to determine the cellular and molecular mechanisms regulating inflammasome activation in glia. Aim 1 will identify the structural components and protein associations of inflammasomes in primary cultures of neurons, astrocytes, and microglia damaged by stretch injury. These studies will delineate which cell types express inflammasomes and will provide insight into the mechanisms leading to cytokine secretion caused by caspase-1 after injury. Aim 2 will identify key inflammasome signaling components in distinct CNS cell types using lentiviral short hairpin (shRNA) vectors that target inflammasome genes and proteins. Related experiments will determine the cellular distribution and temporal sequence of protein expression of inflammasome proteins in spinal cords of normal and injured rats. Experiments in Specific Aim 4 will determine if disruption of inflammasome signaling by antibody neutralization of inflammasome components or lentiviral shRNA silencing of inflammasome genes results in inhibition of inflammasome signaling, thus leading to improved histopathological and behavioral outcomes. These studies will provide critical information about temporal and spatial activation patterns of the inflammasome and identify relevant therapeutic targets to control inflammation following SCI and other neurodegenerative disorders. PUBLIC HEALTH RELEVANCE: Spinal cord injury (SCI) occurs throughout the world with an annual incidence of 15 to 40 million people per year and results in lifelong disabilities. The main cause of SCI in young males is motor-vehicle accidents and most spinal cord traumas occur at the cervical spinal cord level. The proposed research seeks to reduce cell death by inflammation that occurs within days of SCI, and to devise therapies to treat SCI and help in long-term recovery of function. The development of new treatments that can be given in the first hours after SCI may prevent or reverse much of the spinal cord damage resulting from SCI with a goal of restoring normal functioning in behavior.